Remember that the Japanese implementation (Famicom) was actually promoted as a
gaming computer in its time (Famicom is short for Family Computer). Besides a
keyboard and BASIC, there was also a cassette recorder, disk drive, and modem
available.
(Here's some links for those that have never seen them):
http://flickr.com/photos/mims/72177380/in/set-1366263/
http://www.gamersgraveyard.com/repository/nes/peripherals/fc_keyboard.html
http://en.wikipedia.org/wiki/Image:Famicom_Network_System.jpg
http://www.consoledatabase.com/consoleinfo/nintendofamicomdisksystem/index.…
The US version (the NES) came close to being done more like a computer, but
marketing challenges moved it in a different direction. Here's a pic of what
it almost was:
http://gadgets.boingboing.net/gimages/advanced_1.jpg
Keep in mind that the NOAC (Nintendo On a Chip) is probably the most duplicated
and longest running single chip console implementation, making it the most
easily accessible design and money wise.
Marty